90Y-ibritumomab therapy in refractory non-Hodgkin's lymphoma: observations from 111In-ibritumomab pretreatment imaging.
Radioimmunotherapy is an effective treatment for non-Hodgkin's lymphoma (NHL). 90Y-ibritumomab is an antibody targeting CD20 receptors on the surface of lymphocytes. We present observations from our clinical experience with 90Y-ibritumomab in the management of NHL.


METHODS
This was a retrospective study of 28 NHL patients treated with 90Y-ibritumomab. There were 21 men and 7 women, 36-85 y old. A diagnostic dose of 111In-ibritumomab was administered on day 0, and imaging followed immediately and at 24, 48, and 72 h. The doses of 90Y-ibritumomab ranged from 629 to 1,258 MBq (17-34 mCi). Outcomes were compared with the findings of the 111In-ibritumomab scans.


RESULTS
90Y-ibritumomab induced objective responses in 22 of 28 patients. A complete response was noted in 9 patients, a partial response in 9 patients, and a mixed response in 4 patients. Three patients had stable disease, and 3 patients had disease progression. 111In-ibritumomab findings were positive in 19 patients and negative in 9 patients. A complete response was noted in 2 of 19 patients with positive findings and 7 of 9 with negative findings. A partial response was seen in 7 of 19 patients with positive findings and 1 of 9 with negative findings. Disease progression was observed in 3 of 19 patients with positive findings and 0 of 9 with negative findings. The remaining patients had a mixed response or no changes.


CONCLUSIONS
A higher rate of complete response after 90Y-ibritumomab treatment was seen in patients with negative 111In-ibritumomab findings, whereas a higher rate of disease progression despite therapy was noted in patients with positive 111In-ibritumomab findings. This observation suggests that patients with bulky disease may require more aggressive management.
Iagaru
Andrei
A
Division of Nuclear Medicine, Stanford University Medical Center, Stanford, California 94305, USA. aiagaru@stanford.edu
Gambhir
Sanjiv Sam
SS
Goris
Michael L
ML
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007205:Indium Radioisotopes; D008228:Lymphoma, Non-Hodgkin / Q000175:diagnosis* / Q000517:prevention & control / Q000532:radiotherapy* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D016499:Radioimmunotherapy; D012008:Recurrence; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D007205:Indium Radioisotopes; C422802:ibritumomab tiuxetan